Sin Lieth at the Door
by Blue Sailor
Summary: "Of all the sucky things about his twelve-step plan not to backslide, not drinking sucks the most." Set mid season 10. Dean gives up alcohol in an effort to control the Mark of Cain.


**A/N:** This was supposed to be a tag to 10.11 There's No Place Like Home, but it kind of veered off into its own little universe. Many thanks to the marvelous RiverSongTam for her help on this story!

* * *

" _And the Lord said unto Cain, Why art thou wroth? and why is thy countenance fallen? If thou doest well, shalt thou not be accepted? and if thou doest not well, sin lieth at the door. And unto thee shall be his desire, and thou shalt rule over him."_

\- Genesis 4:6-7 (King James version)

* * *

Whiskey burns way worse coming up than it does going down, Dean thinks dully as he leans over the toilet, struggling to be quiet while his stomach heaves.

Of all the sucky things about his twelve-step plan not to backslide, not drinking sucks the most, even more than the health food. Only twenty-four hours in, and he's been crouched in front of this toilet for what feels like forever already, his knees are objecting painfully to the tiled floor beneath them, and his throat feels as though he tried to swallow the First Blade whole. It almost seems like it would be healthier to just knock back a few shots. Or a whole bottle.

Or he could kill a few things with the Blade. He's gone for much longer than twenty-four hours without that, which probably isn't helping his symptoms. Of course, his hands are shaking so much at the moment, he's not entirely sure he could even hold on to it.

The door opens, and light from the hallway cuts through the dark bathroom. "Dean?" says a soft voice.

Dean just groans in response. So much for trying to be quiet.

"You sick?" Sam asks, pushing the door wider.

Dean groans again, squeezing his eyes shut against the light, vainly hoping Sam will take the hint and leave him alone. He isn't sick, technically, but he'd rather not explain to Sam what's really wrong with him. He can hear the faint slap of bare feet on the floor as Sam steps closer, but doesn't lift his head to look. Even if he wanted to meet Sam's eyes, he's too exhausted to move.

He does move, though, when he feels a light brush of fingers against his forehead, leaning away before Sam can feel how un-feverish he is.

"Did you eat something bad, maybe?" Sam asks, backing off a little, but showing no sign of leaving.

"Yeah. Maybe," says Dean, seizing on the excuse. It's sort of true. The egg whites and kale leaves and almonds he's been eating for the last day or so are definitely bad. He hawks up a glob of nastiness from the back of his throat, spits it into the toilet, and then asks, "How did you even know I was in here?"

"You weren't in your room when I went to check on you."

"To _check_ on me?" Dean repeats, momentarily forgetting his misery in a surge of indignation. _He's_ the oldest; if anyone is going to be doing any checking on anyone, it should be him.

Although he has to admit it's kind of hard to do that when you're stuck puking your guts out into the toilet. And he doesn't even have the excuse of illness or food poisoning; he's here because he can't even survive one day without a drink.

His thoughts are interrupted by another brush against his face, this time of a damp washcloth, and he jerks away.

"Leave me alone," Dean growls.

"Stay still," says Sam, reaching out again with the washcloth. "You're a mess."

Dean is far too shaky to move more than a foot away from the toilet bowl, so he's forced to allow his little brother to wipe his face as though he were a five-year-old kid. It's humiliating. If he had the Blade, he thinks, he wouldn't have to put up with this. He could slice that stupid washcloth to tatters, along with the hand holding it.

His stomach gives a sudden roll at the thought, and he leans over the toilet to puke again. Sam lays aside the washcloth, spreads his hand between Dean's shoulder blades, and starts rubbing slow, firm circles on his back. It feels good, comforting, much more than it has a right to.

"Sammy," he gasps, slumping against the toilet when the retching stops, "leave me alone, wouldja? Just go back to bed."

Sam sits back on his heels. "You first."

Dean glares up at him out of the corner of his eye, but Sam's eyebrows are raised in what is clearly a challenge, so, with a sigh, he pushes himself gingerly upright. His stomach protests the movement, but Dean clenches his jaws together and swallows down the nausea. All he has to do is stand up and walk down the hall to his bedroom, and prove to Sam he's not sick. Well, not _too_ sick. Which should be easy because he _isn't_ really sick. Not that Sam has to know that.

Dean's head is starting to pound from thinking about this too much, and Sam is watching him doubtfully. Gritting his teeth, he claws his way to his feet, using the toilet for support. For a moment, he stands there, triumphant; then his body catches up to him, and his head gets light; gray spots dance in his vision, and his legs start to tremble and fold beneath him.

He expects to crash right back down to the floor, but an arm snags around his waist, holding him upright. Next thing he knows, Sam is hauling his arm over his shoulders, clamping him tightly against his side, and dragging him out into the hallway.

Dean thinks he should probably be protesting this manhandling, but it's taking too much of his concentration just to get his feet to stumble along, and his wobbly legs to support at least some of his weight. The bright fluorescent light in the hallway seems to be stabbing through his eyes directly into his brain, and it doesn't take more than ten seconds for him to give up trying to steer himself and close his eyes, trusting Sam to get him back to his room without incident. It comes as a surprise, therefore, when he's deposited onto a mattress that's most definitely _not_ his beloved memory foam.

Dean blinks his eyes into focus, peering around at a desk cluttered with papers, a laptop perched on the nightstand, overflowing bookshelves. Not his bedroom. Sam's.

"What—?" he begins, but Sam is already striding back out into the hallway, leaving him sitting on the edge of the (uncomfortable) bed. Dean hears the door of the supply closet in the hall creak open, a few rattles and thuds as Sam rummages around, and then the sound of his footsteps returning.

"What are you doing?" Dean asks as soon as Sam re-enters the bedroom, an old mop bucket in his hands.

Sam seems to know exactly what he means, because his face gets that challenging look again. "Keeping an eye on you," he replies matter-of-factly.

"Sam, I get that I haven't exactly been in control lately, but I really don't need constant supervision," says Dean. At least, he doesn't need it from Sam. Between the bottle and the Blade, he's already watching himself plenty.

"You're sick, aren't you?" says Sam, fixing Dean with a sharp gaze.

"Yeah," Dean has to agree, cursing himself now for taking that excuse. He drops his eyes to his hands, resting in his lap. The right one is clenched tightly, as though around the hilt of a phantom blade.

"Then I'm keeping an eye on you." Sam steps forward and plunks the mop bucket on the floor beside the bed. "Try not to hurl on my sheets."

He steps away again to close the bedroom door, throwing them into complete darkness, then walks around to the other side of the bed and climbs in. Dean, however, remains sitting rigidly on the edge of the mattress. He's suddenly afraid to move, not because of the nausea, but because he can still feel the Blade nagging at the back of his mind, and what if his longing for it is enough to pull it straight into his hand, like when he lost it fighting Abaddon? What would happen then? Whatever the outcome, it likely wouldn't be very good as far as Sam is concerned.

Dean jumps at a touch on his shoulder.

"Come on," says Sam, in a far gentler tone than he would be using if he could hear Dean's thoughts right now. "Get some sleep. You can sulk when you're feeling better."

Dean doesn't think he'll ever be feeling better—at least not while the Mark of Cain is still on his arm—and he doesn't think he'll be sleeping, either, while the need for the First Blade, or at least a _drink,_ is shuddering through his veins. But Sam's bed, though not nearly as comfortable as his own, is still a lot more comfortable than the bathroom floor. So, when Sam touches his shoulder again, exerting gentle pressure, Dean finds himself sinking down beside him despite his misgivings.

Sam immediately wraps an arm around Dean's ribs and flings one leg over his, anchoring him to the bed, as though worried Dean might float away. The weight of it is strangely reassuring, even though Dean is fairly certain that, as lightheaded as he feels, he won't be floating away any time soon. And then, even though he knows it's probably dangerous for him to be anywhere near Sam, Dean shifts a bit closer, resting his head on Sam's shoulder, feeling his breath ruffling his hair as it slows and deepens into sleep.

Dean matches his breaths to Sam's, and carefully moves his head down a bit, so he can hear the slow, steady thump of his heart. It's warm and soothing and safe, and it doesn't take long for Dean's muscles to relax, his right hand slowly unclenching from its fist to twist loosely in Sam's t-shirt. But, despite the fatigue dragging at his eyelids, Dean doesn't fall asleep. He lies there, awake, until the nausea and lightheadedness are gone, and then he disentangles himself from Sam and slips off down the hall, back to his memory foam.

Somehow, though, it doesn't feel quite as comfortable as Sam's innerspring, and he still can't sleep.

*S*P*N*

As soon as a reasonable hour arrives the next morning, Dean gets up, makes his way into the kitchen, and unenthusiastically takes stock of the ingredients he has to work with. No bacon or syrup or butter. Not even proper eggs.

No splash of whiskey in his coffee, either.

Dean grabs the container of egg whites out of the fridge, keeping his back turned on the cabinet where the bottle of whiskey lives. His hands are shaking again, but he manages to assemble two omelettes without incident, sliding them out of the pan and onto a pair of plates just as Sam wanders in, yawning and unsuccessfully attempting to smooth his wild mop of hair. He grins sleepily, his arm brushing Dean's as he takes one of the plates.

"Feeling better?" he asks.

"Yeah," says Dean. His headache is gone, at least. He sets his own plate on the table with an unnecessary clatter, hoping to God Sam isn't about to bring up last night's sleeping arrangements.

To his relief, Sam says nothing on that subject, although his next topic isn't much better. "Still on the health-food kick, too, huh?" he notes, settling down at the table across from Dean. "You ever gonna tell me what brought that on?"

Dean gives a noncommittal grunt, and takes a large bite of omelette to avoid answering. Not only would that mean admitting just how bad things have gotten with the Blade, but he would also have to tell Sam the real cause of his illness last night. The egg whites actually seem appealing by comparison.

Some of his disgust must show in his expression, though, because Sam frowns at him, his fork halfway to his mouth. "Are you _sure_ you're feeling better?" he asks.

" _Yes,"_ Dean snaps, directing his best glare right back at his brother. And, to prove his point, he takes another bite of omelette. It's tasteless and rubbery, but Sam is watching him carefully, so he makes sure to finish the whole thing, even though it makes him feel like puking again.

Even that doesn't seem to be enough to convince Sam, though. He's annoyingly clingy all day, even following Dean out to the garage and installing himself next to the toolbox when Dean goes to tinker with the '56 Corvette. Dean thinks it was probably a mistake to let Sam get so close last night, because now he seems to think he has permission to brush his fingers against Dean's every time he hands him something from the toolbox, which Dean would consider too touchy-feely for the light of day even if he wasn't having an increasingly difficult time trying to hide the trembling of his hands. It doesn't help that every time Sam touches him, he finds himself wondering what it would be like to cut Sam's wrists with the sharp, jagged tooth at the point of the First Blade. God, he needs a drink.

It's evening by the time Dean finishes with the Corvette. He tightens the last bolt in place, and then lets his arm fall limply across his chest, not wanting to emerge from under the car even though it's dark and cramped and he's dripping with sweat. Dark, cramped places are where he belongs. No temptations there.

Sam would probably question it if Dean decided to start living under a car, though, so he reluctantly slides forward into the bright light of the garage. Sam is already standing, ready to return to the bunker.

"What's for dinner? Salad again?" he asks, smiling as he reaches down to help Dean up.

Dean should have expected the gesture, but he's too busy thinking about how much he would _love_ a drink right now, and before he knows what he's doing, he's smacked Sam's hand violently away.

Sam flinches back, his smile gone. Dean's hands tremble, and he clenches them into fists.

"Dude, quit grabbing at me, will ya?" he growls up at Sam. He can almost feel the well-worn handle of the First Blade in his palm. What if Sam had surprised him while he was in the grip of one of its fantasies? He could have hurt a lot more than his brother's feelings.

Sam is looking angry now. "What's your problem?" he demands. "You didn't seem to mind it last night."

And there it is, there's what Dean's been hoping Sam wouldn't mention, because he _didn't_ mind it last night, or even today really, not nearly as much as he should have.

Dean gets slowly and deliberately to his feet, and looks directly into Sam's eyes. "Just stay away from me, okay?"

Then he walks out of the garage, leaving Sam standing by the Corvette, and doesn't stop until he's locked in his bedroom.

*S*P*N*

He doesn't sleep, of course. At first he just wants a drink, and then he wants the Blade too, and then he's hot, and then he's cold, and then he's convinced he can feel eyes on him from the corner of his room.

He sits up when that feeling hits him, reaches for the gun under his pillow even though he knows there's no way anyone could be in here with him. He waits until he has the gun in his hand, safety off and pointing directly at the corner—wavering slightly because his hands are still shaking—before clicking on the lamp on his bedside table. Light floods the room, rushing to fill every crevice, illuminating the corner Dean's gun is aimed at—and he was right, there _is_ someone standing there.

It's his father, John Winchester.

Beyond the initial thrill of shock, Dean isn't all that surprised to see him. After all, he saw his father's ghost before, that night he killed the yellow-eyed demon. Only that time, John looked proud, and now he looks sad and disappointed.

That's not much of a surprise, either, really.

"Hi, Dad," murmurs Dean. He sighs, and drops the gun onto the bed so that he doesn't have to see it wobbling and shaking in his hand. "Guess I messed up pretty bad this time, huh?" he says. "You gonna lay into me?"

John doesn't answer, doesn't even blink. Just looks at him, sadly.

Somewhere in the depths of Dean's mind, a small voice is whispering that hallucinations are a symptom of alcohol withdrawal, and talking to John probably isn't doing him much more good than talking to himself, but he rambles on, hastening to explain himself.

"You know, I used to wonder how you did it," Dean says, watching his father's face. "You never broke in hell, and I...well, Alistair didn't even have to torture me." He swallows. "He did anyway, just for fun, but...I broke the day he stopped giving me booze."

Dean looks down, shuddering. He can hear that sickening nasal voice saying, "Let's see how you do without your hunter's helper," as clear as if Alistair were in the room, too. Dean looks back up at John, and, with a jolt, he realizes the voice is coming from John's mouth. He scrambles off the bed, retreats until his back is pressed against the door, but the voice continues, "I can't take all the credit. All I did was make you crack. You were the one who crumbled."

And it's true, he did crumble, even after he got out of hell, until there was nothing left except black smoke. And Sam might think he fixed him, but he didn't, because Dean still craves the Blade, craves killing, just like he craves alcohol.

"Well, I get it now," he says after a moment, eyes stinging as he stares at John, who stares right back at him, silent again. "I'm just not as good as you. Never was. I couldn't even carry out your last order. Save Sam, or kill him, right?" A strange, rough chuckle escapes from his mouth. "Yeah...same old, same old."

His throat is stinging too, now. It wasn't just John's last order; it was his first order, too. Watch out for Sam, save Sam. From the fire, from Yellow Eyes, from Ruby, from Lucifer, from the Trials. Always, almost every time, Dean made the wrong choices and screwed everything up. And now, even his attempt to make the right choice—this stupid twelve-step plan of his—is only making things worse. He still can't save Sam, can't prevent him from getting hurt, because sooner or later he won't be paying attention, he'll mess up, he'll give in, and the First Blade will have its way.

And that will be his greatest failure of all.

"I'm sorry," Dean whispers, his whole body shaking now, still pressed against the door. He gropes behind him for the doorknob, fumbling to turn it. "I'm sorry, Dad."

The door swings open. Dean lurches out into the hallway and slams the door shut behind him, so that he doesn't have to face that silence anymore, that judgment. He stands there for a moment, staring at the door, half-afraid that it will open and John—or someone worse—will follow him into the hall. He retreats backwards, keeping the door in sight and wishing he hadn't left his gun sitting on his bed, until he rounds a corner and can't see it anymore.

Dean is shaking harder than ever now, and he's drenched in cold sweat. He desperately wants a shot of whiskey to warm him with its fortifying burn, but he finds his feet taking him to Sam's room instead of to the kitchen. He knows he shouldn't push the door open, but he does it anyway, sees Sam stirring under his covers in the brief spill of light from the hallway that brightens the room before Dean closes the door behind him.

"D'n?" Sam mutters groggily. "Y' okay?"

Dean should say he's fine, make up some excuse, and leave. But instead, he feels his way through the dark, pulls back the covers on the bed, and crawls in next to Sam. And then, once he's there, he can't help sliding over until he's tucked snugly against Sam's side, and can lock his arms around his brother's solid torso.

It's definitely a bad idea to press his face into the crook of Sam's neck, because it would be all too easy close his teeth on the delicate cartilage of Sam's windpipe, bite down, taste the rush of tangy blood, sweeter and more intoxicating than whiskey. It's dangerous, _he's_ dangerous, but Sam is warm and solid and reassuringly real, and Dean isn't planning on pulling away this time.

He's never been good at making the right choices.

*S*P*N*

Dean spends the rest of the night wrapped around Sam, not moving even when he starts to get hot again and his skin turns clammy with sweat. He just lies there, listening to Sam breathe, listening to his heart. The steady rhythm of it dampens the echoes of Alistair's voice in his mind, but even with his eyes closed and his face hidden in Sam's chest, Dean can still see John's face staring at him in the darkness.

He doesn't sleep.

He practically leaps out of bed, though, when Sam wakes up the next morning with a sleepy, dimpled smile, and starts to nuzzle affectionately into his hair. By the time Sam manages to follow him, he's already in the kitchen whisking up two more egg white omelettes, and pointedly ignoring the sidelong looks Sam throws in his direction. He's determined to get through today— _and_ tonight—without incident, or he'll be getting addicted to unmanly sleeping arrangements, next.

A lot harder to ignore than Sam's glances, however, are the flickers of movement he keeps seeing in the corners of his eyes. And while his head feels fine, and his stomach no longer seems to be trying to turn itself inside out, he's sweating bullets and his hands are shaking worse than ever. It's pure luck that he gets the omelettes on the table without dropping anything. He makes sure to take a seat facing away from the liquor cabinet.

"You feeling any better today?" Sam asks him, once they're settled at the table and Dean can't avoid his gaze quite as effectively.

"I was feeling better yesterday," says Dean, concentrating on his omelette. It doesn't taste any better than it did the previous three mornings, but at least he doesn't immediately feel like chucking it up.

"Yeah. Okay," says Sam, clearly not believing him, but thankfully not pressing the matter.

They both head into the library after breakfast. Sam pulls a few books from the shelves, seemingly at random, switches on his laptop, and gets right to work. Dean follows suit, pulling down a few books for himself and spreading them out on one of the tables, but he can't focus. Half the time he's wondering if he could sneak back to the kitchen for some whiskey without Sam noticing. The other half he's staring at the outline of Sam's shoulder blades under the thin pyjama t-shirt he hasn't bothered to change out of, and thinking about how the First Blade would look, buried between them.

It actually makes him feel a bit better when Sam turns up a video of Charlie torturing an old man in Topeka, and they decide to check it out. At least he isn't the only one going off the rails.

*S*P*N*

Two days later, though, he feels much worse. Charlie has just left the bunker, rested and reunited with her dark side, but with her arm in a sling and bruises and cuts all over her face. Just thinking about it makes Dean feel sicker than he has at any point this whole hellish week, because it's all his fault; because while Charlie was attempting to rein in her dark side, Dean gave in to his own.

Sam finds him slumped in a chair in the dark kitchen, a bottle of whiskey on the table before him. He doesn't ask why the bottle is unopened, which means he must have guessed the real cause behind Dean's symptoms. Dean supposes he was stupid to think the food poisoning excuse would fool Sam for long. Just like he was stupid to think a twelve-step plan would be enough to shore up his weakness.

"You gonna tell me to put it back?" Dean asks finally.

Sam folds his arms, leaning against the doorway. "No. That's up to you."

"Yeah, well," mutters Dean, "we've seen how well most of my decisions have gone lately." Sam doesn't answer, and Dean doesn't look at him, afraid that his face will bear the same sad expression he saw on John's. Not liking the silence, he continues, "I just thought if I could get over the booze, I could get over the Blade, too, but….I guess I couldn't do either."

"Really?" says Sam. "Well, I haven't seen you take a drink in a week." Something in his tone makes Dean's eyes snap onto him; he's smiling, and his eyes are so bright Dean has to look away again. "I'd say that's a step in the right direction, wouldn't you?"

Dean finds himself unable to answer; his throat is suddenly too tight for speech.

"Come on," says Sam, turning from the doorway. "You gonna mope all night or are you gonna help me research that Mark?"

Dean leaves the bottle of whiskey sitting unopened on the table, and follows Sam.


End file.
